Process for the making of slide fasteners, means for carrying out this process and fastener chain made by said process

ABSTRACT

The invention provides a process, for the manufacture of a continuous chain of two rows of linking components for the making of slide fasteners out of two rows each consisting of a thread shaped into a spiral inside the whorls of which a longitudinal cord or strand is positioned, the improvement that the said cord or strand is placed in an intermediate position in the width of each row by assembling the two corresponding rows while causing the linking components of each row to penetrate more deeply between the whorls of the other, in order to push back the length-ways inside cord or strand in the latter row, whereafter these two rows are fixed on to two supporting tapes by means of lines of stitching, the stitches of said lines being inserted inside the free spaces between the cord or strand inside each row and the portions connecting the successive whorls thereof.

FASTENERS, MEANS FOR CARRYING OUT THIS PROCESS AND FASTENER CHAIN MADE BY SAID PROCESS Horst Jakob, Choisy-le-Roi, France Assignee: Societe Financiere Francaise de Licences et Brevets, Choisy-le-Roi, France Filed: Dec. 3, 1971 Appl. No.: 204,593

Inventor:

Foreign Application Priority Data Dec, 8, 1970 France 7044071 References Cited UNITED STATES PATENTS 12/1939 Prentice MacFee .1 29/410 United States Patent 1 1 [111 3,750,260 Jakob Aug. 7, 1973 [5 PROCESS FOR THE MAKING OF SLIDE 3,634,922 I I 1/1972 Burbank et al. 29 410 Primary Examiner-Thomas H. Eager Attorney-Arthur B. Colvin [57] ABSTRACT The invention provides a process, for the manufacture of a continuous chain of two rows of linking components for the making of slide fasteners out of two rows each consisting of a thread shaped into a spiral inside the whorls of which a longitudinal cord or strand is positioned, the improvement that the said cord or strand is placed in an intennediate position in the width of each row by assembling the two corresponding rows while causing the linking components of each row to penetrate more deeply between the whorls of the other, in order to push back the lengthways inside cord or strand in the latter row, whereafter these two rows are fixed on to two supporting tapes by means of lines of stitching, the stitches of said lines being inserted inside the free spaces between the cord or strand inside each row and the portions connecting the successive whorls thereof.

6 Claims, 5 Drawing Figures PATENTEllAus 1 ms SHEET 1 [1F 2 I nventor 6 0/65 r c/A K0 6 Attorney PROCESS FOR THE MAKING OF SLIDE FASTENERS, MEANS FOR CARRYING OUT TIIIS PROCESS AND F ASTENER CHAIN MADE BY SAID PROCESS This invention relates to the manufacture of a slide fastener wherein each of the two rows of linking components consists of a continuous thread shaped into a spiral. I i

In fasteners of this kind, the linking components proper are generallymade by crushing or suitably deforming one of the ends of each whorl of the corresponding spiral. There are already a great many processes whereby such units can be made, and-which are then fixed by stitching onto supporting tapes.

To facilitate this latter operation, the spirals constituting the linking components usually have a varying pitch so as to leave the widest possible space between two successive whorls. Thus, the stitches can easily be inserted in each of these spaces. This enables the rows of linking components to be fixed at a high rate, e.g. by means of a chain stitch or any other suitable kind of stitch.

However, the rows of linking components have the disadvantage of not being perfectly held in the transverse direction. In fact, the whorls of the corresponding spirals can slip sideways under the stitching. It. is true that various means have already been suggested for overcoming this disadvantage. However, these are not entirely satisfactory.

Thus, it has already been suggested that the whorls of each spiral should be so geometrically shaped as to make it impossible for them to slip under the stitching. However, this complicates the shaping of the spiral from a continuous thread, and consequently more complex equipment is needed for this operation.

It has also been suggested that each row of linking components should be held transversally by fixing it by means of stitches inserted through a cord or similar item threaded inside each spiral beforehand. This solution does indeed have the advantage of giving a perfect transversal hold. However, it entails that the stitches have to be inserted with great accuracy so as to go through the cord provided inside each spiral. Now, the need to observe such a degree of accuracy has the disadvantage of reducing the rate of manufacture, and making it necessary to use accurate equipment. Moreover, the cord positioned inside each spiral has to be made of textile or similar fibres, so that the stitches can go through it.

This invention accordingly relates to a process and a manufacturing device enabling such rows of linking components to be held perfectly in the transverse direction without entailing the disadvantages listed above.

This process likewise involves inserting a cord or strand length-wise inside each spiral making up a row of linking components. However, in accordance with this process, this cord or strand is placed in an intermediate position in the width of each row, and it is then fixed onto the corresponding supporting tape by means of stitches inserted in the free spaces between the longitudinal strand or cord and the portions connecting the corresponding whorls of the spiral.

In order to position the inside cord or strand in the middle of each of the two complementary rows of linking components of a fastener chain, these are assembled so that the linking components penetrate deeper than in the case of a normal joining of these two rows, so that the linking components of each of them push back the inside cord or strand of the other row into the required position. Then, after this operation, the continuous chain so assembled is subjected to pressure with a roller, or other suitable implement, so that the inside cord or strand of each row is pressed into the inside surface of the branches of the whorls of the row, which holds it in position.

The invention also relates to a manufacturing device for carrying out this process. Further, it also includes fasteners made by this process and with this device.

Other features and advantages of the invention will be apparent from the following description which should be read with reference to the accompanying drawing given by way of indication only, and wherein:

FIG. 1 is a partial view from above of a row of linking components used in carrying out this process;

FIG. 2 is a view from above showing the application of this process;

FIG. 3 is a sectional view along the line III-III in FIG. 2;

FIG. 4 is a partial view from above showing the fixing by stitching of two rows of linking components on two tapes serving to support them;

FIG. 5 is a corresponding sectional view along the line V-V in FIG. 4.

As already stated, this process involves the use of a row of linking components consisting of a continuous thread la or lb shaped into a spiral. The pitch of this varies so that the successive whorls 2 are as far apart as possible, and the two branches of each whorl may, for this purpose, be superimposed one on the other.

At one of their ends, the various whorls comprise a flattened or deformed part 3a or 3b designed to form a linking compopent in the fastener to be made.

Such a row of linking components can be made in various ways, using one or other of the known processes for the purpose. During the shaping of each spiral la or lb, a longitudinal cord or strand 4a or 4b is positioned inside the whorls so that it extends longitudinally over the whole length of the spiral. However, this cord or strand may also be positioned inside the whorls after the corresponding spiral has been shaped. Here again, various known processes may be used for the purpose.

Theseetion of the strand 4a or 4b is such that it only takes up part of the space inside the whorls of the corresponding spiral. By some suitable means, this strand or cord is brought into proximity with the linking components 3a or 3b, unless it is already in such a position right from the time it is positioned inside the spiral.

Then, in accordance with the essential characteristic of this process, this strand is placed in an intermediate position in the width of the corresponding row. For this purpose, the two spirals 1a and lb so formed are assembled by making the linking components 3a or 3b of each of them penetrate deeper than in the case of normal joining of these two rows. To do this, a joining device is used, consisting of a part 5 comprising a Y- shaped channel 6 whose two top forks 7a and 7b take the two rows of linking components la and lb.

The linking components of these rows are made to join at the place where the two forks 7a and 7b of the channel 6 meet. This coupling is obtained by exerting a pull, in the direction of the arrow F,, on the continuous chain emerging from the channel 6.

In accordance with an important characteristic of this device, the width E of this channel is narrower than that of the standard slide which will subsequently be mounted on this chain. This lesser width E is calculated so that the linking components 3a and 3b of each row penetrate deeper between those of the other row than during subsequent normal joining of these two rows. In these circumstances, the linking components of each row push back the strand 4a or 4b which is inside the whorls of the other row.

Each strand is thus moved away from the linking components of the row inside which it is positioned, and brought to the middle part of the whorls of that row. In this position, this strand subdivides each space between two whorls into two separate parts, respectively situated on the same side as the linking components 3a or 3b, and on the side of the portions 13 connecting the whorls, i.e.:

a space 14 designed to take the linking component 3a or 3b of the other row,

and a space designed to serve as a space for inserting a stitch of the fixing seam.

This assembly device also comprises a pressing roller 8 positioned over the chain obtained by assembling the two rows la and lb. These are subjected to heating at that point, so that by virtue of the crushing of the whorls by the roller, the inside strands 4a or 4b are pressed into them and a slight indentation 9 is formed.

The purpose of the indentations so made is to hold the inside strands 4a and 4b in the position they are occupying at that moment after having been pushed back as described earlier, this position being substantially along the median axis of each of the rows la and lb.

In these circumstances, each of these inside strands leaves a comparatively large space 10 between itself and the portions 13 connecting two successive whorls. Now, this space makes it easy subsequently to stitch each of the rows la and lb on to supporting tapes lla and llb, as shown in FIGS. 4 and 5. This operation is effected on each row by means of a line of stitches 12 inserted in the space between each inside strand 4a or 4b and the portions 13 connecting two successive whorls.

The sewing needle is thus inserted into the space 10 previously mentioned and each stitch thus closely holds the corresponding whorl against the tape 11a or llb.

However, it should benoted that the very presence of the inside strand 4a or 4b causes each row of linking components to be perfectly held in the transverse direction on the corresponding supporting tape.

In fact, taking row la, this is held in the direction of the arrow F by the fact that if the whorls slip under the stitches, the linking components come up against the inside strand 4a, which in turn comes up against the stitching.

In the opposite direction F,, the whorls of the spiral are held in position in the usual way by the fact that in this case the portions 13 connecting them come up against the stitching 12.

As may be seen, the inside strand 4a thus plays an essential part in the transversal retention of each row of linking components on the corresponding supporting tape. Nevertheless, the presence of this inside strand in no way hampers the subsequent fixing of each row of linking components by stitching. In fact, contrary to what was the case in some earlier manufactures, the stitches are not inserted through this cord but outside it, in the spaces 10 between this cord and the portions 13 connecting the whorls. Now, as already mentioned, these spaces are large enough for the stitches to be inserted easily and at high speed.

The continuous fastener chain obtained by this process can then be cut into longer or shorter lengths in order to make a number of separate slide fasteners. The manufacture of these is obviously completed by positioning a control slide on each of them, as well as end stops made by some means.

As already stated, this invention also relates to fasteners made by application of the process described above.

However, it goes without saying that these fasteners are not limited to the single example of embodiment described above. The same applies to the device for producing them, as well as the manufacturing process itself.

In this connection, it should be noted that the lengthways cord or strand positioned inside each row of linking components may be made of various materials. In fact, it may consist of a cord based on textile fibres, as was the case in some earlier fasteners. Nevertheless, this is no longer essential in the case of this process, since the fixing seam is sewn outside this cord. In these circumstances, this may perfectly well consist of a synthetic resin filament or thread, which is, in fact, especially good.

Moreover, each row of linking components may be fixed by stitches other than those shown as an indication in FIGS. 4 and 5.

Thus, several lines of stitching can be provided for, and they may possibly be positioned on each side of the inside strands 4a or 4b of the corresponding row of linking components. It is also possible to provide for stitching with chain-stitches straddling the inside strand 4a or 4b by means of two needles positioned on either side thereof.

I claim:

1. The method of manufacturing a chain for slide fasteners comprising two connectible rows each including a thread shaped into a spiral having successive whorls, said spiral including linking components along one longitudinal marginal edge, portions connecting adjacent whorls along the other marginal edge, and a longitudinal cord or strand within the whorls and between the edges, comprising the steps of disposing a strand between the whorls of said spirals, causing the linking components along said one marginal edge of each of said spirals to enter between successive whorls of the spiral of said other row, thereafter shifting said rows toward each other to cause said cords to be shifted toward said other marginal edges of said rows.

2. The method of claim 1 and including the step of subjecting said rows which have been shifted toward each other to pressure applied in a direction normal to the longitudinal axis of said rows, thereby to press said strands into the portions of said whorls engaging said strands.

3. The method of claim 1 and including the step of stitching each said row to a support tape by stitches disposed in the spaces between said cord and said other marginal edge of said row.

4. Apparatus for manufacturing a chain for making slide fasteners, said chain comprising two connectible rows each including a thread shaped into a spiral having successive whorls, said spiral including linking components along one marginal longitudinal edge, portions connecting adjacent whorls along the other marginal edge, and a longitudinal cord or strand within the whorls and intermediate the said edges, said apparatus comprising a Y shaped joining channel having side walls, said channel including first and second converging branches leading to a stem, the transverse spacing of said side walls of said stem being less than the sum of the distances between said other marginal edges and said linking components, means for simultaneously advancing two said rows through said branches and out said stem progressively to connect said linking components and thereafter shift said rows toward each other between the marginal edges of the other row.

0 I l II! 

1. The method of manufacturing a chain for slide fasteners comprising two connectible rows each including a thread shaped into a spiral having successive whorls, said spiral including linking components along one longitudinal marginal edge, portions connecting adjacent whorls along the other marginal edge, and a longitudinal cord or strand within the whorls and between the edges, comprising the steps of disposing a strand between the whorls of said spirals, causing the linking components along said one marginal edge of each of said spirals to enter between successive whorls of the spiral of said other row, thereafter shifting said rows toward each other to cause said cords to be shifted toward said other marginal edges of said rows.
 2. The method of claim 1 and including the step of subjecting said rows which have been shifted toward each other to pressure applied in a direction normal to the longitudinal axis of said rows, thereby to press said strands into the portions of said whorls engaging said strands.
 3. The method of claim 1 and including the step of stitching each said row to a support tape by stitches disposed in the spaces between said cord and said other marginal edge of said row.
 4. Apparatus for manufacturing a chain for making slide fasteners, said chain comprising two connectible rows each including a thread shaped into a spiral having successive whorls, said spiral including linking components along one marginal longitudinal edge, portions connecting adjacent whorls along the other marginal edge, and a longitudinal cord or strand within the whorls and intermediate the said edges, said apparatus comprising a Y shaped joining channel having side walls, said channel including first and second converging branches leading to a stem, the transverse spacing of said side walls of said stem being less than the sum of the distances between said other marginal edges and said linking components, means for simultaneously advancing two said rows through said branches and out said stem progressively to connect said linking components and thereafter shift said rows toward each other beyond said connected position, and pressure means positioned to engage said connected rows emerging from said stem for applying pressure to said rows in a Direction normal to the longitudinal axis of said rows, thereby to press said strands into the portions of whorls of said spirals engaging said strands.
 5. The apparatus of claim 4 and including heating means for heating the components subjected to said pressure means.
 6. The apparatus of claim 4 wherein the transverse dimension of said stem is calculated to position the linking components of each row substantially centrally between the marginal edges of the other row. 